<template>
    <div>
      <h1>选项式API</h1>
      <h2>数字：{{ count }}</h2>
      <button @click="add" class="add">加+</button>
      <button @click="sub" class="sub">减-</button>
    </div>
  </template>
  
  <script>
  export default {
    name: "App",
    data() {
      return {
        count: 0
      };
    },
    methods: {
      add() {
        this.count++;
      },
      sub() {
        this.count--;
      }
    },
    mounted() {
      console.log("mounted");
    }
  };
  </script>
  <style>
  .add {
    background-color: red;
  }
  .sub {
    background-color: green;
  }
  </style>
  